docs: def set_document(request, doc_id, body, errors):
      """ Simple handler for set document
      :param request: aiohttp.web.Request
      :param errors: aiohttp_apiset.exceptions.ValidationError
                     optional param for manual raise validation errors
      :return: dict
      """
      if doc_id in DB:
          errors['doc_id'].add('Document already exists')
  
      if errors:
          raise errors
  
      body['doc_id'] = doc_id
      DB[doc_id] = body
  
      # dict response for jsonify middleware
      return body